Wireless, or radio frequency (RF), communications systems have been used extensively in telecommunications and data networks. Some wireless networks operate on a single radio frequency channel, while other wireless networks operate on multiple channels. In both single-channel and multichannel wireless networks, co-channel interference (CCI) is known to be a factor that can affect wireless system capacity and, consequently, user quality of experience (QoE).
Radio resource management (RRM) techniques generally offer system-level control of co-channel interference by properly adjusting certain system parameters in the time, frequency, power, and spatial domains. Radio resource management can enable relatively efficient use of the limited radio resources and radio network infrastructure to provide improved system capacity and enhanced QoE. Typical control strategies include, for example, enhanced inter-cell interference coordination (eICIC), frequency reuse, power control, beamforming, or a combination of these.
Coordinated multi-point transmission (CoMP) techniques have allowed multiple base stations to jointly serve a mobile station. In CoMP, the serving base stations act as a distributed antenna array to transmit signals from the network to the mobile device. Spatial domain beamforming and precoding typically have been used to improve spatial multiplexing gain. However, the performance of these techniques can be sensitive to channel estimation error.
In general, transmitting to receivers with an increased power improves the signal-to-noise ratio (SNR), which enhances data rate and increases spectrum efficiency. However, high transmit power can lead to increased co-channel interference. Conventional power control techniques have focused on transmit power settings for individual transmit points.
Solutions employing coordination of multiple transmit points within a network, or radio coordination (RC), to reduce or control co-channel interference have typically modeled the entire network or fixed groupings of transmit points. Ideally, an RC solution would jointly optimize the transmission parameters of all transmit points throughout the network. However, regarding relatively large networks, a network-wide optimization solution may include an unacceptable level of complexity. Further, if network congestion occurs at relatively few, relatively isolated transmit points, optimization of the entire network may not be necessary to ensure acceptable performance.